Open-source Koofr alternatives

Nextcloud Server is a platform for keeping your files, contacts, calendars and other data on a server of your choosing. Content is synchronized across your devices, can be shared with other people for viewing or collaboration, and stays under your control rather than with a large cloud provider. It grew out of the ownCloud lineage.

Functionality can be expanded through hundreds of apps in its App Store, including Calendar, Contacts, Mail and Video Chat. Security measures include encryption mechanisms, a public bug bounty program and two-factor authentication. There are several ways to get a Nextcloud: sign up with a provider, install the server yourself on your own hardware or with a ready-to-use appliance, buy a device that comes with it preinstalled, or find a service provider to host it for you.

The server is written in PHP and JavaScript under the AGPL-3.0 license. Nextcloud GmbH also offers an Enterprise edition aimed at public sector, education and company users. It suits households, schools and organizations that want to replace commercial cloud storage and office suites with something they run themselves.

Cloudreve is a self-hosted file management and sharing system with support for multiple storage backends. You can keep files on local disk, on a remote node, or with providers including OneDrive, S3-compatible services and several Chinese clouds such as Aliyun, Tencent, Huawei and Qiniu, and clients transfer data directly to the provider.

Everyday file features include drag-and-drop upload of files and folders with parallel, resumable transfers, batch download, compressing and extracting archives, WebDAV access across all storage providers, and background downloads through Aria2 or qBittorrent using one or more download nodes. Media metadata can be extracted so files can be searched by metadata or tag. Multiple users and groups are supported, and share links for files and folders can carry an expiry date. Videos, images, audio and ePub files preview online, and text, Markdown, diagrams and Office documents can be edited.

Cloudreve is written in Go and licensed under GPL-3.0, with a project homepage, online demo, documentation and Telegram and Discord communities. It suits individuals and small organizations that want a private, Chinese-ecosystem-friendly alternative to commercial cloud drives.

OpenList is a community-driven fork of AList, created in 2025 and written in Go. Its README says the fork aims to provide resilient, long-term governance and to defend open source against trust-based attacks. The project is maintained by the OpenList Team and released under the AGPL-3.0 license, with a stated commitment to complete code openness and transparent modifications.

AList is known as a program that lists and manages files stored on many cloud drives, and the repository topics for OpenList mention Aliyun Drive and Baidu Pan. The maintainers publish a disclaimer asking users to note that OpenList is not affiliated with similarly named third-party projects or paid proprietary software. They state that the project has no paid plans or commercial deployments, that its documentation and API services rely on charitable Cloudflare resources, and that downstream projects must respect the AGPL and avoid impersonating the name.

Cryptomator encrypts files on your own device before they reach a cloud storage service. It presents an encrypted vault as a virtual drive, so you work with files as if they were on a USB flash drive while only encrypted data is synced. It runs on Windows, macOS and Linux, is written in Java and is released under the GPL-3.0 license.

It works with any cloud service that synchronizes with a local directory, including Dropbox, Google Drive, OneDrive, MEGA, pCloud, ownCloud and Nextcloud. Files are protected with AES encryption using 256-bit keys, file names are encrypted, and the folder structure is obfuscated. You can keep as many vaults as you like, each with its own password.

The security design uses scrypt key derivation and cryptographically secure random numbers, and it wipes sensitive data from memory quickly. Encryption is client-side, so no account is needed and no data is shared with an online service. The project is provided free of charge and relies on donations and sponsors for development.

Seafile is a file synchronization and sharing platform written mainly in C. Beyond keeping folders in sync across devices and sharing them with others, it describes a newer way of organizing files using extensible file properties and flexible views. Topics also tie it to wikis, Markdown, knowledge management and document management.

The project's homepage could not be fetched while preparing this entry, so the details here come from the repository description, its topics and general knowledge of the product. Seafile is known for client apps on desktop and mobile, libraries as the unit of syncing and sharing, and an emphasis on reliable syncing of large numbers of files.

The core server is open source, with its license listed as 'Other' on GitHub, and the vendor also sells a professional edition and offers hosted service. You can run it on your own servers, which suits teams and organizations that want private cloud storage under their control.

Filestash began as a Dropbox-like file manager that speaks many storage protocols, including FTP, SFTP, S3, SMB, WebDAV and IPFS along with about twenty more. It has since grown into a wider file management platform built around three products: a web client for browsing files in a browser, a native client for syncing data to devices, and gateways that expose storage over other protocols.

Its architecture is plugin-driven, so anything beyond the lean core lives in a plugin and requirements are met by adding or writing plugins rather than forking. The web client is written in vanilla JavaScript, and APIs and gateways can expose data over SFTP, S3, FTP, WebDAV, MCP and AS2. Authentication integrations can go as far as delegating login to a WordPress site and using its roles for access control.

A workflow engine automates actions on files by chaining steps on events, ranging from Slack or email notifications to managed file transfer pipelines. Filestash is written in Go and released under the AGPL-3.0 license, and repository topics point to uses in document management and archiving.

ownCloud Core is the server component of ownCloud Classic, a self-hosted platform for file storage, synchronization and sharing. It is the foundation on which apps such as Activity, Calendar and Contacts are built, and is written in PHP and JavaScript.

It ships with servers for WebDAV, CalDAV and CardDAV, an app plugin architecture, backends for external storage, support for encryption, user and group management, and a REST API. The server runs on PHP with MySQL, MariaDB, PostgreSQL or SQLite, and is also available as a Docker image on Docker Hub. Its topics point to federated sharing and enterprise use.

ownCloud Classic is licensed under AGPL-3.0, and installation is covered by the official manual. For the next-generation platform, the project points to ownCloud Infinite Scale. Contributors follow a rebase workflow with signed commits and DCO sign-off, and enterprise support is available from the vendor. It suits organizations and individuals who want to keep files on their own servers instead of a public cloud.

Kodbox is a web-based file manager that can act as a private cloud disk for individuals or an enterprise network drive. It is a redesign of the earlier KodExplorer project and also includes a web code editor, so websites can be edited directly in the browser. The operating experience is modeled on a desktop file explorer, including drag and drop, keyboard selection, and quick search.

A key capability is multi-storage support: files can live on a local disk, FTP, WebDAV, or object storage such as Alibaba Cloud OSS, Tencent Cloud COS, Qiniu, MinIO, or any S3-compatible service. It previews, edits, and plays many office and media formats online, and supports sharing links, collaboration, and fine-grained permission control.

Kodbox runs on Linux, Windows, or macOS and, according to the README, needs only PHP. Clients are available through the web, mobile browsers, iOS, Android, desktop, and WebDAV mounting. The input does not state a license or pricing model, so check the vendor site for current terms. It suits teams and individuals who want to keep documents on their own infrastructure.